A volcanic marker (92 ka) for dating deep east Antarctic ice cores

Tephra layers recorded in East Antarctic ice enable reliable linking over long distances and, when correlated with well-dated eruptions in the source area, provide absolute ages for improving the accuracy of model-based ice chronology. We used chronostratigraphic information and grain-specific geochemical data (major elements by electron microprobe and trace elements by LA-ICP-MS) to suggest that a tephra layer from the EPICA-Dome C and Dome Fuji ice cores is the distal counterpart of the Mt. Berlin (Marie Byrd Land province, West Antarctica) pyroclastic unit 40Ar/39Ar dated to 92.5 +/- 2.0 and 92.2 +/- 0.9 ka. Such one-to-one correlation, which is proposed here for the first time for the East Antarctic deep climatic archives, provides independent age constraints for glaciological modelling of core timescales. (c) 2006 Elsevier Ltd. All rights reserved.